Some Areas of Ramsar, a city in northern Iran are among the world’s wellknown inhabited areas with highest levels of natural radiation. Annual exposure levels in these areas are up to 260 mGy y‐1 and the mean exposure rate is about 10 mGy y‐1 for a population of about 2000 residents. If elevated levels of natural radiation as high as a few hundred mSv per year is detrimental to health and...

although there are substantial experimental, epidemiological and clinical evidences that high doses of ionizing radiation cause cancer and other detrimental biological effects, the health effects of human exposure to chronic low dose radiation exposures are still poorly known. people in some areas around the world live in dwellings with radiation and radon levels as much as more than 200 times ...